General Aspects带 Ecology Found throughout the environment Very simple nutritional requirements Not usually in normal flora unless hospitalized or immunocompromised BIOL 533 Lecture 13
BIOL 533 2 Lecture 13 General Aspects • Ecology – Found throughout the environment • Very simple nutritional requirements – Not usually in normal flora unless hospitalized or immunocompromised
General Aspects带 Virulence Possess number of structural factors and toxins Resistant to most common antibiotics Surprising that they do not constitute problem in general population BIOL 533 Lecture 13
BIOL 533 3 Lecture 13 General Aspects • Virulence – Possess number of structural factors and toxins – Resistant to most common antibiotics – Surprising that they do not constitute problem in general population
Microbial Physiology and structure Morphology Straight or slightly curved Gram bacterial Polar flagella; motile Some strains appear mucoid due to polysaccharide capsule Some produce diffusible pigments Pyocyanin(blue), fluorescin (yellow), pyorubin (red-brown) BIOL 533 Lecture 13
BIOL 533 4 Lecture 13 Microbial Physiology and Structure • Morphology – Straight or slightly curved Gram— bacterial • Polar flagella; motile – Some strains appear mucoid due to polysaccharide capsule – Some produce diffusible pigments • Pyocyanin (blue), fluorescin (yellow), pyorubin (red-brown)
Microbial Physiology and structure Physiolog Carbohydrate fermentation Use only few CHO using oxidative pathways Glucose, ribose, gluconate Oxygen is terminal electron acceptor Presence of cytochrome oxidase Distinguishes from Enterobacteriaceae Anarobic growth can occur by using mitrate as terminal acceptor BIOL 533 Lecture 13
BIOL 533 5 Lecture 13 Microbial Physiology and Structure • Physiology – Carbohydrate fermentation • Use only few CHO using oxidative pathways – Glucose, ribose, gluconate • Oxygen is terminal electron acceptor • Presence of cytochrome oxidase – Distinguishes from Enterobacteriaceae – Anarobic growth can occur by using mitrate as terminal acceptor
Virulence factors Adhesins: pili and nonplus adhesins Production of neuraminidase enhances adherence Alginate(mucoid layer): Protects against phagocytosis and facilitates adherence to host cells BIOL 533 Lecture 13
BIOL 533 6 Lecture 13 Virulence Factors • Adhesins: pili and nonpilus adhesins – Production of neuraminidase enhances adherence • Alginate (mucoid layer): Protects against phagocytosis and facilitates adherence to host cells